Wheel manufacture



Sept. 19, 1961 1. WEBB WHEEL MANUFACTURE 2 Sheets-Sheet 1 Filed July 16, 1957 I: hut/M wkj BR Hm N W Jm L Sept. 19, 1961 L. l. WEBB WHEEL MANUFACTURE 2 Sheets-Sheet 2 Filed July 16, 1957 FIGA L./. WEBB INV NTOR. 5e. BY a- ATTOlQ/VEKS'- United States Patent 3,000,081 WHEEL MANUFACTURE Lester I. Webb, Detroit, Mich, assignor to Ford Motor Company, Dearborn, Mich., a corporation of Delaware Filed July 16, 1957, Ser. No. 672,220 10 Claims. (Cl. 29-1563) This invention relates to the metal working art and is more particularly directed to a method for economically and repetitiously producing wheels employable either as compressor or turbine wheels.

The development of the turbine and compressor art has been seriously impeded by the ditficulties inherent in the production of turbine and compressor wheels. These difiiculties stem in part from the fact that the blades must be shaped to a precise airfoil configuration and must be secured to a hub in such a way as to resist creep over long periods of time at high temperatures and under heavy centrifugal forces. This invention has been developed to enable such critical wheels to be produced more economically and with ordinary production labor and facilities.

This invention will be explained in connection with the drawings in which FIGURE 1 is a perspective view of a typical turbine blade, and

FIGURE 2 is an elevational view of a turbine wheel at an early stage of manufacture, and

FIGURE 3 is a similar elevational view of a turbine wheel at a later stage of manufacture, and

FIGURE 4 is a cross section of a portion of the completed Wheel prior to removal from the fixture, and

FIGURE 5 is an elevational view of a portion of the completed turbine wheel prior to removal from the fixture.

In the manufacture of turbine wheels according to this invention a large number of identical blades of appropriate chemical analysis and air foil configuration are first produced: In FIGURE 1 the blade is denominated generally as and the blade base as 11. It will be seen that the blade 10 takes a conventional air foil shape. Blade base 11 is shown in a so-called fir tree configuration which serves to prevent radial detachment of the blade from the hub under heavy centrifugal stress. Blade base 11 may also be provided with one or more depressions 12 or elevations 13 to prevent axial displacement of the blade 10 from the hub during operation.

The fir tree configuration shown is given by way of example only. Any mechanically strong base structure resistant to displacement in all directions and particularly resistant to centrifugal stress may be employed.

As a second step in the production of the turbine wheel the assembly shown in FIGURE 2 is produced. In FIG- URE 2 a die block 13 encloses a locating ring 14. Within ring 14 are assembled in their final position the proper number of blades 10. Reverting to FIGURE 1, it is preferred to grind end faces 15 and edges 16 of blade base 11 to close tolerances to produce an exact assembly in ring 14. When blades 10 are assembled in ring 14 within die block 13, the edges 16 of the individual blade bases closely abut each other to form a band 17. Clamping members 18 are employed to temporarily hold the assembly together.

FIGURE 3 depicts a further step in the production of the turbine wheels. The purpose of this step is to rigidly, but temporarily secure the assembled blades 10 in their proper position to enable them to remain fixed during a subsequent operation. This is accomplished by filling the annulus defined by band 17 and ring 14 with a low melting and molten metal. This metal is then permitted to solidify at which time it securely binds all of the blades into the desired final position. While any suitable low melting metal may be used as the binding material it is preferred to use metals similar to the composition sold commercially as Kirksite. After this alloy has solidified, centering disc 20 may be removed and all of the blades 10 will be found to be firmly locked into place.

The assembly of blades, die and Kirksite is now placed in a rapidly acting press preparatory to the forging of the hub about the bases 11 of blades 10. A hub blank which has been previously heated to forging temperature is now inserted in the space vacated by centering disc 20. This forging temperature will usually be at least 2100" F. and often is as high as 2350 F.

The rapidly moving press mentioned above now applies a heavy axial pressure to hub blank 21 and causes hub blank 21 to flow radially in all directions and to flow into the spaces between the bases 11 of blades 10. These bases 11 project inwardly and beyond band 17. The axial force applied by the press to hub blank 21 should be suflicient to cause the metal to flow around the projections provided by the fir tree configuration given to bases 11. The flow of hub blank 21 in this manner is shown in FIGURES 4 and 5. These figures of drawing necessarily represent the somewhat idealized condition of complete flow which in practice can only be approximated.

As a typical example of an operation of this type a turbine wheel having an external diameter from tip to tip of the blades of 12 inches and a band diameter of 8 inches with a complement of forty blades was produced according to this invention. The blades were firmly held in position with Kirksite and the hub material was a conventional 18-8 stainless steel slug. Forging temperatures varied from between 2025 F. and 2225 F. and the forging pressure was 1200 tons. All of these wheels were successfully forged.

I claim as my invention:

1. In a process for manufacturing wheels including a plurality of radial blades secured to a central hub with said blades being provided with bases having irregularly shaped root portions, the steps of arranging a plurality of blades in positions corresponding to their final position in the finished wheel and with the bases of the blades forming a substantially continuous band concentric with the wheel, rigidly securing the blades in this position, placing a highly heated metallic hub blank within the band formed by the blade bases and applying a heavy axial pressure to the blank to cause the metal of the blank to form the wheel hub by flowing radially into contact with the irregularly shaped root portions of the blade bases and to secure the blades firmly to the hub.

2. In a process for manufacturing wheels including a plurality of radial blades secured to a central hub with saidblades being provided with bases having irregularly shaped root portions, the steps of arranging a plurality of blades in positions corresponding to their final position in the finished wheel and with the bases of the blades forming a substantially continuous band concentric with the wheel, rigidly securing the blades in this position by pouring molten metal around at least a part of the nonroot portion of the blades, placing a highly heated metallic 1 hub blank within the band formed by the blade bases and applying a heavy axial pressure to the blank to cause the metal of the blank to form the wheel hub by flowing radially into contact with the irregularly shaped root portions of the blade bases and to secure the blades firmly to the hub.

3. In a process for manufacturing wheels including a plurality of radial blades secured to a central hub with said blades being provided with bases, the steps of arranging a plurality of blades in positions corresponding to their final position in the finished wheel and with the bases of the blades forming a substantially continuous band. concentiiewiththewheel, said blade bases being provided with at least one irregularity on each blade for anchoring the blade to the hub, rigidly securing the blades in this position, placing a highly heated, metallic. hub blank within the. band formed by. the blade bases and applying a heavy axial pressureto the blank. to, cause the metal of the blank to form the wheel'hub by flowing radially into contact with the blade. bases andto secure the blades firmly to the hub and inrlocking relationship with the blade base irregularity.

4. In a process for manufacturing'wheels including a plurality of radial blades'secured to a central hub with said blades being provided with said bases, the steps of arranging a plurality. of bladesv in positions corresponding to their final. position in the finished wheel and with the bases of the blades forming. asubstantially continuous band concentric with the wheel; said blades bases being provided with at leastone irregularity on eachblade for anchoringthe blade to ahub, the configuration of such irregularities being such that all sections through the irregularities and perpendicular to the axis of the finished wheel are identical, rigidly securing the blades in this position, placing a highly. heated metallic hub blank within the band'formed by, the blade bases and applying a heavy axial pressure to the blank to cause the metal of the blank to form the wheel hub byv flowing radially into contact'with the blade bases and into the blade base irregularities to secure the blades firmly into'the hub.

5. In aprocess forv manufacturing wheels including a plurality of radial blades secured toa' centralhub with said blades being provided with bases, the steps of arranging a plurality ofrblades;v in positions corresponding to their final position in the finishedwheel and with the bases ofthe blades forming a substantially continuous band concentric with the wheel, said blades bases being in the fir tree form, rigidly securing the blades in this position, placing a highly heated metallic hub blank within the band formed by the blade bases and applying a heavy axial pressure to the blank to cause the metal of the blank to form the wheel hub by flowing radially into contact with the blade bases and to secure the blades firmly to the hub and. in locking relationship with the blade base fir tree configuration.

6. In a process -for manufacturing wheels including a plurality of radial/blades secured to a central hub with said blades being provided with bases, the steps of arranging a plurality of blades in positions corresponding to their final position in' the finished wheel and with the bases of the blades forming asubstantially continuous band concentric with the wheel, said blade bases being in the fir tree form, rigidly securing the blades in this position by pouring molten metal around at least a part of the non-root portion of the blades, placing a highly heated metallic hub blank within the band formedby the blade bases and applying a heavy axial pressure to the blank to cause the metal of the blank to form the wheel hub by flowing radially into contact with the blade bases and into the fir tree configuration to secure the blades firmly into the hub.

7. In a process for manufacturing wheels including a plurality of radial blades secured to a central hub, the steps of arranging a plurality of blades in positions corresponding to their final positions in the finished Wheel and with means on said blades forming a substantially continuous annular band, rigidly'securing the blades in this position, said blades being provided with means for securing the blades to the central hub, placing a highly heated metallic hub blank within the annular band formed by the means on said blades and applying a heavy axial pressure to the blank to causethe metal of the blank to form the wheelhub by flowing radially into contact with the means for securing the blades to the central hub and to secure the blades firmly to the hub.

8. In a process for manufacturing wheels including a plurality of radial blades secured to a central hub with said blades being provided with bases having irregularly shaped root portions, the, steps. of arranging a plurality of blades in positions corresponding to their final position in the finished wheel and with the bases of the blades forming a substantially continuous band concentric with the wheel, placing means for resisting radial pressures on said blades in contact with the tips of said blades, rigidly securing the blades in this position, placing a highly heated metallic hub blank Within the band formed by the blade bases and applying a heavy axial pressure to the blank to cause the metal of the blank to form the wheel hub by flowing radially into contact with the irregularly shaped-root portions of the blade bases and to secure the blades firmly to the hub, said means in contact with the tips of said blades retaining said blades in their original radial position.

9. in a process for manufacturing wheels including a plurality of blades secured to a central' hub with said blades being provided withrbases having means for securing the blades to the central hub, the steps of arranging a plurality of blades in positions corresponding to their final position in the finished wheel and with the bases of the blades forming a substantially continuous band concentric with the wheel, rigidly securing the blades in this position, placing a highly heated metallic hub blank within the band formed by the blade bases and applying a heaxy axial pressure to the blank to cause the metal of the blank to formthe wheel hub by flowing into contact with the said means for securing the blades to the central hub.

10. In a process for manufacturing wheels including a plurality of blades secured to a central hub with said blades being provided with bases having means for securing the blades to the central hub, the steps of arranging a plurality of blades in positions corresponding to their final position in the finished wheel and with the bases of the blades forming a substantially continuous band concentric with the Wheel, rigidly securing the blades in this position by pouring molten metalaround at least a part of the blades, placing a highly heated metallic hub blank within the band formed by the blade bases and applying a heavy axial pressure to the blank to cause the metal of the blank to form the wheel hub by flowing into contact with said means for securing the blades to the central hub.

References Cited in the file of this patent UNITED STATES PATENTS 310,846 Owen et al. Ian. 13, 1885' 1,329,277 Van Dusen Jan. 27, 1920 1,551,342 Steenstrup Aug. 25, 1925 2,432,819 Schumacker Dec. 16, 1947 2,639,119 Greenwald May 19, 1953 2,753,624 Taylor July 10, 1956 FOREIGN PATENTS 023281b/49 Germany May 9, 1956 

